In recent years, according to the rapid development of wireless communication, insufficiency of usable frequencies is becoming a serious problem. Therefore, it is desired to effectively use frequencies. As a method of effectively using frequencies, there is a method of performing transmission in an optimum wireless communication system adapted to a radio wave environment. When the wireless communication system adapted to the radio wave environment is selected, an interference identifying device that extracts characteristics of an interference signal in the radio wave environment and identifies the interference signal plays an important role. There have been proposed various systems concerning the interference identifying device.
The interference identifying device in the past calculates, with respect to radio wave environment measurement data, amplitude information such as an amplitude probability distribution as a feature value of a waveform of an interference signal and compares the amplitude information and a threshold to thereby estimate presence or absence of occurrence of interference with a communication signal. See, for example, Patent Literature 1.
For example, as disclosed in Patent Literature 2, there has been proposed a method of acquiring a peak value of noise with respect to a frequency used by a wireless apparatus, if the peak value is equal to or smaller than a reference value, determining that communication can be performed, and securing the quality of communication.